In the trucking and heavy equipment industry, particularly in the tractor-trailer vehicle industry, loads of various sizes and weights must be handled. Accordingly, various types of trailers and specialized trailing implements have been utilized to handle such loads. Furthermore, vehicle operators must comply with specific laws governing the permissible weight of vehicles that travel on freeways and highways. Typically such laws specify the maximum allowable weight per axel of the vehicle. To facilitate compliance with these laws, the trucking industry has long since developed various adjustable frame components to change the weight distribution on the vehicle axels and bring the vehicle into compliance with weight laws.
Many traditional trailers utilize a tandem axel frame assembly which nests inside the main frame assembly of the trailer. The tandem axel frame assembly is moveable relative to the main frame assembly to change the position of the tandem axels relative to the main trailer frame. Changing the position of the tandem axels varies the distribution of weight on all of the vehicle axels.
Operators of tractor-trailer vehicles must frequently change the position of the trailer tandem axels relative to the trailer frame to comply with the particular vehicle weight laws. Several changes may be required during a single trip where the load is sequentially reduced. The weight distribution will change for a given amount of movement of the tandem axel relative to the other portions of the vehicle. To change the position of the tandem axels of the trailer, a mechanical locking pin which holds the tandem axel frame in place relative to the main trailer frame must be released, typically, with the operator having to depart from the cab to manually release it. The operator then re-enters the cab portion of the vehicle and inches the vehicle forward or backward while maintaining the tandem axels in the same place. The operator while in the cab is required to guess as to how much movement of the vehicle will result in the desired amount of relative frame movement. After making an initial guess, the operator is required to climb out of the vehicle cab to observe the actual amount of frame movement, and then reenter the vehicle cab to make further adjustments.
Accordingly, there is a need for a device to assist vehicle operators, including but not limited to tractor-trailer vehicle operators, in adjusting the relative position of a tandem assembly.